TABLE 2.

Various bactericidal efficiencies of different streptococcus strains against S. aureus strain Newmana

Streptococcus strainBactericidal efficiency (IK6) (log10 CFU ± SD)Concn of H2O2 (mM) in supernatant of 7.5 log10 CFU of S. pneumoniae culture
S. pneumoniae (Pn-20)6.4 ± 0.31.60 ± 0.58
S. pneumoniae (Pn-20ΔspxB)1.2 ± 0.8<0.05
S. pneumoniae (Pn-20ΔlytA)6.2 ± 0.11.60 ± 0.87
S. pneumoniae (TIGR4)6.3 ± 0.30.12 ± 0.07
S. pneumoniae (TIGR4ΔspxB)1.4 ± 0.2<0.05
S. pneumoniae (Rx1)5.8 ± 0.50.20 ± 0.17
S. pneumoniae (Rx1ΔlytA)5.8 ± 0.60.43 ± 0.05
S. gordonii3.8 ± 0.6<0.05†
Group A streptococcus0*<0.05†
Group C streptococcus0*<0.05†
  • a IK6, maximal S. aureus Newman inoculum killed by 106 CFU of streptococci at 6 h. IK values are averages from at least three independent experiments±SD. *, detection level = 50 CFU/well; †, detection level = 0.05 mM.